Question

why does a desert cooler cool better an a hot dry day

Answer 1

this is so because on a hot dry day temperature is high and humidity is less which helps in better evaporation. due to the higher rate of evaporation it gives better cooling effect

Answer 2

A desert cooler works on the principle of evaporation. On a hot dry day the temperature of the atmosphere is high and the humidityos low , which increases the rate of evaporationand thus will cause more cooling effect.